On Fri, 11 Feb 2022 at 09:56, Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> wrote: > > > On 2/11/22 10:52, Matthew Auld wrote: > > On Fri, 11 Feb 2022 at 09:49, Thomas Hellström > > <thomas.hellstrom@xxxxxxxxxxxxxxx> wrote: > >> > >> On 2/10/22 13:13, Matthew Auld wrote: > >>> Starting from DG2+, when dealing with LMEM, we assume that by default > >>> all userspace allocations should be placed in the non-mappable portion > >>> of LMEM. Note that dumb buffers are not included here, since these are > >>> not "GPU accelerated" and likely need CPU access. > >>> > >>> In a later patch userspace will be able to provide a hint if CPU access > >>> to the buffer is needed. > >>> > >>> Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx> > >>> Cc: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx> > >>> --- > >>> drivers/gpu/drm/i915/gem/i915_gem_create.c | 9 +++++++++ > >>> 1 file changed, 9 insertions(+) > >>> > >>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c > >>> index 9402d4bf4ffc..cc9ddb943f96 100644 > >>> --- a/drivers/gpu/drm/i915/gem/i915_gem_create.c > >>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c > >>> @@ -424,6 +424,15 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data, > >>> ext_data.n_placements = 1; > >>> } > >>> > >>> + /* > >>> + * TODO: add a userspace hint to force CPU_ACCESS for the object, which > >>> + * can override this. > >>> + */ > >>> + if (!IS_DG1(i915) && (ext_data.n_placements > 1 || > >>> + ext_data.placements[0]->type != > >>> + INTEL_MEMORY_SYSTEM)) > >>> + ext_data.flags |= I915_BO_ALLOC_GPU_ONLY; > >>> + > >> WRT previous review comment here, it would be easier to follow if the bo > >> was marked as a GPU only buffer regardless. Then for example capture and > >> other functions where it actually matters can choose to take action > >> based on, for example, whether the BAR is restricted or not? > > Yeah, I completely forgot about this, sorry. Will fix now. > > Actually you did reply, but I forgot to reply to that :). Hmm, should we just drop the IS_DG1() check here(that was my first thought), or go further and still apply even regardless of placements? i.e it would be set on integrated > > /Thomas > >
